1. Field of the Invention
The present invention relates to a livestock watering system, and more particularly, but not by way of limitation, to a livestock watering system adapted to selectively circulate water in response to the temperature of the water in the drinking basin so as to prevent freezing of the water during low temperature conditions.
2. Brief Description of the Prior Art
Providing a fresh supply of water for livestock in the winter season of the year when sub-freezing temperature conditions are encountered presents a difficult problem for ranchers and the like. Numerous systems have heretofore been suggested for providing a supply of fresh water for livestock when sub-freezing temperatures are encountered. One especially effective watering system heretofore known is the watering system disclosed in my co-pending patent application entitled "IMPROVED LIVESTOCK WATERING SYSTEM", U.S. Ser. No. 718,566, filed Apr. 1, 1985. The livestock watering system disclosed in pending patent application Ser. No. 718,566 comprises a housing, a drinking basin supported by the housing, a reservoir disposed within the ground so as to be positioned below the frost-line of the ground, and a water circulation assembly for selectively circulating water between the reservoir and the drinking basin. A flow control valve, disposed in a lower portion of the drinking basin, is connected to a pressurized water source such that a substantially constant level of water is maintained in the drinking basin. A temperature sensing assembly adapted to sense the temperature of the water in the drinking basin is operably connected to the water circulation assembly such that the water circulation system can be selectively activated between an on mode and an off mode in response to the temperature of the water in the drinking basin.
Typical of other prior art systems are the recirculating livestock watering system disclosed in U.S. Pat. No. 3,306,263 and the livestock watering station disclosed in U.S. Pat. No. 4,309,962.
While most of the prior art systems have incorporated various means to control the level of the water in a drinking basin, and/or for recirculating water between a drinking basin and a reservoir to prevent freezing of the water in the drinking basin during the winter, many of such prior art systems have possessed certain inherent problems in that such systems are expensive to operate due to the energy requirements of constantly circulating the water; and in many instances, such systems do not effectively prevent freezing of the water in the drinking basin when the water is exposed to low temperature conditions. In addition, many of the livestock watering systems heretofore known utilize complex mechanical structures requiring substantial maintenance.